Bearing for a timepiece pivot



, Max ch 17, 1970 F. MART] 3,500,632

BEARING. FOR A 'IIMEPIECE PIVOT Filed Sept. 9, 1968 2 Sheets-Sheet 1 ,L253m, 1 \afaf mi 2 2 5 2 2 3 F/G FIG 4 ll: III'I/ X F/G.5

INVENTOR. FRITZ MART! ATTORNEYS March 17, 1970 F. MART! 3,500,632

' BEARING, FOR A TIMEPIECE PIVOT Filed Sept. 9, 1968 2 Sheets-Sheet 2FIG. 6 FIG. 8

\\\\p1 v/ P 251 2/ mmuufi q WW 9 x F/G.9 FIG.

INVENTOR. FRITZ MART] M, WW1

ATTORNEYS United States Patent 3,500,632 BEARING FOR A TIMEPIECE PIVOTFritz Marti, La Chaux-de-Fonds, Switzerland, assignor to Portescap, LePorte-Echappement Universal S.A., La Chaux-de-Fonds, Switzerland FiledSept. 9, 1968, Ser. No. 758,515 Claims priority, applicationSwitzerland, Sept. 11, 1967, 12,496/ 67; Oct. 16, 1967, 14,516/ 67 Int.Cl. G04b 13/02, 31/00 US. Cl. 58-140 19 Claims ABSTRACT OF THEDISCLOSURE A timepiece bearing having a drilled jewel and an end piecewhich is held adjacent to the back of the drilled jewel. The end piecehas at least one radial notch at its periphery which extends into thecentral portion of the end piece and exposes corresponding portions ofthe drilled jewel allowing the bearing to be lubricated without removalor dismantlement.

The present invention relates to timepieces generally and morespecifically to bearings for timepiece pivots either of theshock-absorbing type wherein a drilled jewel and an end piece are heldin place at a small distance from each other by a spring, or of thecapped-jewel type wherein a drilled jewel and an end piece are set at aslight distance from each other in a mount or setting.

Today the technique of cleaning timepieces or watches by ultrasonicsallows a watch repairman to clean a watch without disassembling thewatch movement. However, although cleaning modern bearings is possiblewithout disassembling the entire watch movement, this is not true foroiling the bearings after the cleaning. In order to cause a drop of oilto penetrate between the drilled jewel and the end piece of thebearings, the bearings must be taken apart. Thus, there has been anincreasing demand for bearings, both of the capped-jewel and of theshockabsorbing type, which can be oiled in assembled condition.

One way to provide a bearing which can be oiled in assembled conditionis to construct the bearing such that the end piece has a smallerdiameter than its associated drilled jewel. Such constructions areillustrated in my copending application Ser. Nos. 704,826 and 704,827which show, in one case, the small diameter end piece supported at aslight distance behind the drilled jewel by a spring having an oilopening and, in the other case, the small diameter end piece supportedat a slight distance behind the drilled jewel in a mount having an oilopening. These bearings described in my copending application requirespecial springs or mounts to hold the small end piece.

The timepiece pivot bearing, either of the cappedjewel and theshock-absorbing type, to which this present invention pertains,comprises a bearing body, a drilled. or holed, jewel and an end piece,sometimes referred to as an end jewel or an end stone. In theshock-absorbing bearing the drilled jewel is press-fitted into thebearing body which has an annular mount, and the end piece, in the formof a fiat disc, is held by a spring at a small distance from the drilledjewel. In the capped-jewel bearing, the drilled jewel and the end pieceare both set in an annular mount or setting at a small distance fromeach other.

This timepiece pivot bearing to which this present invention pertains ischaracterized by the fact that the end piece of the bearing, whosediameter is of conventional size, that is, about the same size as orgreater than the diameter of its corresponding drilled jewel, has at itsperiphery at least one notch which extends radiall almost to the centerof the end piece to enable a drop of oil to be deposited between the twojewels of the bearing without disassembling the bearing. This drop ofoil is drawn in between the drilled jewel and the end piece of thebearing towards the hole of the drilled jewel and is retained there bycapillary action.

The object of the present invention is to provide a simplified bearingstructure of either the capped-jewel or shock-absorbing type which canbe cleaned and also reoiled without being taken apart.

Another object of this invention is to provide bearings for timepiecepivots of the type having a drilled jewel and an end piece which can becleaned and also reoiled without being taken apart wherein the diameterof the end piece is conventional in size, that is, about the same sizeas or greater than the diameter of its corresponding drilled jewel, andwherein the need for special mounts or springs to hold the end piece iseliminated.

Other objects and features of the invention will become apparent tothose skilled in the art as the disclosure is made in the followingdescription of the invention as illustrated in the accompanying drawingin which:

FIGURE 1 is an axial section through a shock-absorbing bearingconstructed in accordance with this invention;

FIGURE 2 is a plan view of the bearing shown in FIGURE 1;

FIGURE 3 is a partial view in larger scale showing the end piece andspring of the bearing shown in FIG- URE 1;

FIGURE 4 is an axial section through a shock-absorbing bearingconstructed in accordance with this invention illustrating anotherembodiment of this invention;

FIGURE 5 is a plan view of the bearing shown in FIGURE 4;

FIGURE 6 is an axial section through a cappedjewel bearing constructedin accordance wit-h this inventron;

FIGURE 7 is a top-plan view of the bearing shown in FIGURE 6;

FIGURE 8 is an elevational view of the bearing shown in FIGURE 6.

FIGURES 9, 10, and 11 show various shaped end pieces used in bearingsconstructed in accordance withthe present invention.

The bearing shown in FIGURES 1-3 is a shock-absorbing bearing forbalance staff pivot. It comprises a bearing body 1 in which there restsfreely on a conical bearing surface an annular mount 2 with conicalupper portion 2. Drilled jewel 3 is press-fitted in the annular mount 2.The drilled jewel 3 with its mounts 2, 2' swings making it possible in aknown manner to absorb the radial shocks which a balance stalf pivot(not shown) may incur.

An end piece, or end jewel, or stone 4, consisting of a cylindrical dischaving a diameter larger than that of the drilled jewel 3, is heldelastically on an inner shoulder of the upper conical portion 2 of themount 2 by a lyreshaped spring 5 removably held in a known manner in atransverse passage of shape in the bearing body 1.

The end stone 4 has a radial notch 6 of trapezoidal, or rectangular,shape at its pheriphery which, as viewed from above by one oiling thebearing, uncovers a corresponding sector of the drilled jewel 3. Thenotch 6 extends almost to the center of the end piece, and a drop of oilcan be introduced through this notch from above, by means of an oil-pikefor example, into the area between the two jewels without dismountingthe bearing. To insure that the drop of oil is drawn towards the axialhole of the drilled jewel 3, and that it is held there by capillaryaction, it is advisable, in practice, to position the point at the endof the notch that is closest to the center of the end piece at adistance d from the center of the end piece which is equal to 2 to 4times the minimum radius of the hole of the drilled jewel.

In the embodiment shown in FIGURES 13, the end stone 4 can turn in itsseat as a result of impact or ultrasonic cleaning. Therefore, afterrotation due to impact or cleaning, the notch 6 of the end piece mightoccupy any angular position. It might, for instance, be in the positionshown in FIGURE 3, that is, below the arm of the spring 5. Thus, it isimportant that the shape and dimensions of the notch, as well as theshape and dimensions of the portion 5 of the spring, be such that theend piece cannot escape from the spring as a result of shifting due to ashock and to insure that the bearing, with its shock-absorbing function,remains intact.

Also, it is desirable when the end stone is positioned so that the arm 5of the spring covers the notch 6, that the shape and the dimensions ofthe portion 5 of the spring, as well as those of the notch, be such thatthe notch is only partially covered and that lubrication is stillpossible.

In the embodiment of FIGURES 4 and 5, the notch 16 is arc-shaped. Thelyre spring 15 has an extending tab on each side of the axis X-X whichis bent towards the drilled jewel and extends into the notch 16 toprevent the end piece, or end stone, 14 from turning. In this way theend piece, or stone, 14 is prevented from accidentally arriving in aposition which permits the notch to free itself from the spring.

Of course, it should be noted that the end piece may have more than onenotch, for instance two diametrically opposite notches, and that theshape of the notches may differ from those shown in FIGURES 3 and 5.

The capped-jewel shown in FIGURES 6, 7 and 8 comprises an annularbearing body 21 in which there is press-fitted in the lower portion adrilled, or holed, jewel 22 and in the upper portion a disc-shaped endpiece, or end jewel, or stone, 23 having a diameter larger than thediameter of the drilled jewel. This end piece is held at a slightdistance from the drilled jewel by an annular shoulder 21 of the bearingbody.

The end stone 23 has at its periphery two diametrically opposite radialnotches 24 of trapezoidal, rectangular, triangular, or other suitableshape which, as viewed from above by a person oiling the bearing,uncover corresponding sectors of the drilled jewel 22. Each notch 24penetrates almost to the center of the end piece. A drop of oil can beintroduced through either of these notches from above, by means of anoil-pike for example, into the area between the two je-wels withoutdisassembling the bearing. To insure that the drop of oil is drawntowards the axial hole of the drilled jewel 22 and that it is retainedthere by capillary action, it is advisable, in practice, to position thepoint at the end of each notch which is closest to the center of the endpiece at a distance d from the center of the end piece which is equal to2 to 4 times the minimum radius of the hole of the drilled jewel.

Although the bearing shown makes oiling possible without disassemblingthe hearing, it may be desirable for some reason to remove the endpiece. To provide for the removal of the end piece, the bearing body 21is provided with a diametral passage 25 which permits the point of atool to be introduced between the end piece and the drilled jewel toforce the end piece out from the bearing body.

The variant embodiments of the end piece shown in FIGURES 9 and haveonly single radial notches 26, and 27, respectively. The variant shownin FIGURE 11 has two notches 28 of generally U shape. These FIG- URES 9,l0, and 11 show only a few of the various notches that may in fact beemployed. Thus, it should be realized, of course, that these notches,are only illustrative and that the number and shape of the radialnotches may differ from those shown without departing from thisinvention.

The invention has been described hereinabove in preferred embodiments,but it is to be understood that the invention is in no way confined tothe particular embodiments shown and described and that numerousmodifications or alterations may be made therein without departing fromthe spirit of the invention.

I claim:

1. A bearing for a timepiece pivot comprising a drilled jewel and an endpiece held at a slight distance from said drilled jewel, a bearingsupport structure for holding said drilled jewel and said end piece inspaced relationship, said drilled jewel and said end piece defining aspace therebetween to receive oil, said end piece having at least onenotch at its periphery extending into its central portion, said notchexposing portions of said drilled jewel and defining an opening leadingfrom the top and side of said end piece into said space between saiddrilled jewel and said end piece, whereby oil can be deposited throughsaid opening into said space between said drilled jewel and said endpiece without disassembling the bearmg.

2. A bearing for a timepiece pivot as described in claim 1 wherein saidend piece has two notches.

3. A bearing for a timepiece pivot as described in claim 1 wherein saidnotch of said end piece is generally U-shaped.

4. A bearing for a timepiece pivot as described in claim 1 wherein saidnotch of said end piece is generally trapezoidal.

5. A bearing for a timepiece pivot as described in claim 1 wherein saidend piece is circular and the edge of said notch of said end piece isdefined by an arc.

6. A bearing for a timepiece pivot as described in claim 1 wherein saidend piece is circular and the edge of said notch of said end piece isformed by a chord.

7. A bearing for a timepiece pivot as described in claim 1 wherein saidend piece has a diameter substantially the same as the diameter of saiddrilled jewel.

8. A hearing for a timepiece pivot as described in claim 1 wherein saidend piece has a diameter greater than the diameter of said drilledjewel.

9. A hearing for a timepiece pivot as described in claim 1 wherein theend of said notch is located at a distance from the center of the endpiece equal to 2 to 4 times the minimum radius of the hole of thedrilled jewel.

10. A bearing for a timepiece pivot as described in claim 1 wherein saidbearing support structure includes a mount, said end piece and saiddrilled jewel being pressfitted in said mount and being held thereby ata slight distance apart.

11. A bearing for a timepiece pivot as described in claim 10 whereinsaid mount is annular and said end piece is disc-shaped.

12. A bearing for a timepiece pivot as described in claim 10 whereinsaid bearing body is provided with a radial passageway which permits thepoint of a tool to be introduced between the end piece and the drilledjewel to force out the end piece.

13. A hearing for a timepiece pivot as described in claim 10 whereinsaid end piece has two generally U-shaped notches at its periphery.

14. A shock-absorbing bearing for a timepiece pivot as described inclaim 1 wherein the bearing support structure includes a mount, saiddrilled jewel being press-fitted in said mount, and a spring, said endpiece being held by said spring at said slight distance from saiddrilled jewel.

15. A shock-absorbing bearing for a timepiece pivot as described inclaim 14 wherein said mount is annular, said end piece disc-shaped, andsaid notch in said end piece extends radially almost to the center ofsaid end plece.

16. A shock-absorbing bearing for a timepiece as described in claim 14wherein said spring has two extending tabs which are bent towards thedrilled jewel and which extend into the notch to contact the sides ofthe notch when the end piece moves whereby the end piece is preventedfrom rotating.

17. A shock-absorbing bearing for a timepiece pivot as described inclaim 14 wherein said spring contacts the surface of said end piece tohold it at a slight distance from said drilled jewel and wherein saidend piece can move with respect to said spring into a position such thatsaid notch is beneath said spring, said spring being adapted totransverse said notch and to contact at least one surface adjacent saidnotch when said notch moves into said position such that said notch isbeneath said spring, whereby the end piece is held by said spring whensaid notch is beneath said spring.

18. A shock-absorbing bearing as in claim 17 wherein said end piece canrotatably move with respect to said spring, said rotation being causedby shock or by cleanmg.

19. A shock-absorbing bearing as in claim 17 wherein said spring isadapted to transverse said notch over an area smaller than the area ofthe notch whereby a portion of the notch remains exposed allowing forthe introduction of oil into said space between said drilled jewel andsaid end piece.

References Cited UNITED STATES PATENTS 2,671,309 3/1954 Marti et al58140 2,886,943 5/1959 Haguenin 58140 FOREIGN PATENTS 1,049,614 8/1953France.

153,880 6/ 1932 Switzerland. 286,182 2/ 1953 Switzerland. 353,685 5/1961 Switzerland.

STEPHEN J. TOMSKY, Primary Examiner S. A. WAU, Assistant Examiner

